Process of printing textiles



Patented Oct. 12, 1954 PROCESS OF PRINTING TEXTILES Herman Weisz and Durward Costner, Rock Hill,

S. 0., assignors to Rock HillPrinting & Finishing Company, Rock Hill, S. 0.

N Drawing. Application May 26, 1951, Serial No. 228,531

'2 Claims. l

The present invention relates to improvements in textile printing wherein a printing paste is used as the means of depositing color and binder for color onto a fabric. The printing paste we refer to is a water-in-oil emulsion carrying a dispersed substantially water insoluble pigment color. The internal phase of the emulsion we refer to is water, the external continuous phase of the emulsion we refer to is an alkyd resin in an organic solvent.

In the commercial carrying out of the textile printing, roller printing machines are used. The cloth to be printed is passed between an intaglio engraved roller and the print machine cylinder. A color pan and brush furnish the printing paste, or color, up to the engraved roller which in turn transfers the color to the cloth. Only that portion of the roller that is etched below the surface puts color on the cloth, as a steel knife, or doctor blade, scrapes all color from the smooth surface of the print roller.

In this specification the term printing paste refers to the color-resin-water paste as actually applied to the cloth in the printing operation.

According to the present methods employed in the practice of textile printing, the printing paste is generally prepared by mixing a clear emulsion with a color paste. The clear emulsion consists of one to four percent alkyd resin solids, twelve to twenty percent organic hydrocarbon solvent and 65 to 87 percent-water.

This is a water-in-oil type emulsion in which the J water forms the discontinuous internal phase and the resin-solvent forms the external continuous phase. The color paste consists ofa substantially water insoluble pigment dispersed in an alkyd resin emulsion in the proportions of about 25 percent pigment, 1-5 percent resin and 60 percent water.

The printing paste is classified according to its light color strength as follows:

(a) If one part color paste is mixed with-nine parts of clear emulsion, the resultant printing paste is nine light.

(b) If one part pigment paste is mixed with six parts of clear emulsion, the resultant light color is said to be six light.

as .now p a t ced are rea hed. .howerer. when t cause difiicultiesoccur on the intaglio roller.

When one light and two light printing pastes are used, the non-etched portion of the printing intaglio roller rapidly becomes dry and sticky with the printing color which makes it difficult for the knife or doctor blade to clean roller thoroughly. The roller then retains color on the non-etched portion of the roller where it should not be in addition to holding color in the etched out areas where it should be. The printin paste sodeposited on the non-etched surface of the roller and not scraped off by the doctor blade is removed from the smooth surface of the roller by the cloth as the .cloth passes over the roller with the undesirable result that streaks of color are'transferred to the cloth in those areas where no color was intended to appear. As a result of this condition, which is invariably encountered when printing pastes of two light and one light strength are used, the present art is limited to colors of four light, six light and of lower pigment concentration if clean prints are to be obtained.

In order to more clearly point out the methods of the current art and the limitations thereof and to clearly define the scope of our present invention, we append the following table showing the varieties of pigment concentrations that occur in a typicallight color series.

Table of a typical light color sefies Percent Parts of Total Pi ment liggf g Clear Parts of 5 in Final Light Number Paste" Emul- Printing @35 Light b weight sion by Paste" 3 Color Y weight Yield s 8 Printing Paste It will be seen f-rom the table that the pigment concentration from four light to two light increases 3.33 percent, an amount greater than the increase .in the entire range between ten ligh n f u li h For purposes of nomenclature, we refer to light colors-;ef four light to fone light as concentrated colors, and to colors of five light to twenty light as normal colors."

The concentrated colors, also known as concentrated color printing pastes, contain 5.00 percent pigment or more than 5.00 percent pigment and comprise the class of printing pastes within the scope of the present disclosure.

By methods known in the present state of the art of textile printing, concentrated color printing pastes cannot be used successfully on high speed cloth printing machines because when concentrated color pigment pastes are used on these machines, the pigment deposits on the non-etched smooth roller surface, causing scratching of the roller and deposit of color onto areas of the cloth intended to be free ofcolor.

We have observed that the undesirable deposits an the smooth surface of the intaglio printing roller which occur when the pigment ratio in relation to the alkyd resin is high are deposits largely of the particular chemical pigment used to make the color paste. The pigment is adhesive to the roller and is not scraped off by the doctor blade as it should be and as occurs when normal colors are used. Part of this undesirable pigment deposit dries out, and due to the rotation of the roller against the doctor blade, the dry pigment, caught between the doctor blade and the smooth surface of the roller, scratches the roller and abrades the smooth surface thereby greatly shortening the life of the roller. The other part of the undesir able pigment, deposits on areas of the cloth where no color was intended to be deposited in the normal operation of the printing process.

It is an object of the present invention to modify the color made from chemical pigments and alkyd resins in water-in-oil emulsions so that they can be used to print cloth in roller printing machines when concentrated color printing pastes are used and when printing pastes in the ranges of one light, two light and three light are used, with color streaking and spotting and deposits of pigment on areas of cloth not corresponding to the etched areas of the intaglio roller. It is also an object of this invention to modify the concentrated printing pastes so that in their use no deposit of undesirable color occurs on the non-etched portion of the printing roller.

It is also an object of this invention to prolong the life of intaglio printing rollers when concentrated printing pastes are used by so modifying the pastes that no deposit of dry pigment occurs between the doctor blade and the print roller thus avoiding scratches and abrasion of the roller.

We have found that the addition of an organic solvent soluble water repellant to a concentrated color prevents the drying of pigment agglomerates on the non-etched surface of the intaglio roller with the result that concentrated colors can be used successfully during long production operations without any drying of pigment on the non-etched portions of the roller, and with the result that no scratching of the rollers occurs, and with the result that no deposit of color is transferred to those portions of the cloth intended to be left blank.

We have found siloxane polymers particularly suitable for the carrying out of our invention. By siloxane polymers, we refer to the entire group of polysiloxanes and include the resins and oils derived from di-methyl-di-hydroxy silane, di-ethyl-di-hydroxy silane, phenyl- 4 methyl-di-hydroxy silane, ethylg-phenyl-di-Zhydroxy silane and the like by means of dehydration condensation.

The polysiloxanes or mixtures thereof contemplated within the scope of this invention are those which can be represented by the general formula (RrySiO) xR wherein R represents an organic hydrocarbon radical, 11 represents a whole number from one to three, inclusive, and :1: represents any whole number.

The polysiloxanes Silicone 81182 and Antifoam A are typical examples of the polysiloxanes we prefer to use.

We find that relatively small amounts of the water repellant agents cause the effect we desire. We have found that less than 5 percent of our water repellants on the weight of the concentrated printing paste is effective. The amount of siloxane polymer water repellant we prefer to use is dependent on which siloxane polymer we prefer to use; certain organo polysiloxanes are effective in a concentration as low as 0.0001 percent. Generally one part in 3000 in the proportion we prefer to use.

By the term water repellant as herein used, we intend to include anti-wetting agents, oilto-oil wetting agents, oil-to-metal wetting agen -all of these designations are descriptive of the properties of the polysiloxanes contemplated herein and represented by the general formula (R/ySiO)mR.

By the term alkyd resin, we refer to the condensation products derived from polybasic acids and polyhydric alcohols containing monobasic drying or non drying organic acid. We refer to alkyd resins of the type normally supplied in solution in an organic solvent under the commercial name Glyptal. The alkyds may be used alone or in combination with other resins as minor ingredients. Such other resins that may be used are urea-formaldehyde, melamine formaldehyde, polymers of unsaturated hydrocarbons such as butadiene, isoprene, cyclopentadiene and with other agents such as soap, organic amines, a cationic or anionic detergent.

By the term pigment, we refer to any organic or inorganic colored fine powder substantially insoluble in water.

For purposes of explanation, we have outlined a common practice of preparing the printing paste by admixture of a clear emulsion with a color paste. We do not, however, limit ourselves to these steps in the preparation of our concentrated printing pastes. In the carrying out of our invention, we have successfully employed a more direct procedure as follows:

The resin and solvent are mixed, water added to form the water-in-oil emulsion, a pulp pigment added, followed by the polysiloxane water repellent. The concentrated printing paste can thus be prepared in one operation;

The pulp pigment referred to consists of a pigment containing water only. Such pigments, known as pigment pulps or press cakes" are familiar to those versed in the art of chemical pigment manufacture and represent an intermediate step in the manufacture of dry colors. The use of pigment pulp or pulp pigmen in place of color paste represents an alternate means of preparing concentrated printing pastes. When this procedure is used, by the term concentrated printing paste, we refer to print- 7 EXAMPLE 1 A blue concentrated.printingxpaste was prepared by mixing the following:

V Partsby weight Blue Color Paste A 1000 Clear emulsion of alkyd resin 'R; 3000 The printing paste represents a typical three light printing paste. It was attempted to print this color onto cotton cloth in a roller printing machine. After 20 minutes operation it was necessary to stop the machine. Excessive streaks and deposits of color appeared on the cloth in areas intended to be free of color. The pigment had dried out and built up beneath the doctor blade; the intaglio roller was sticky with a thin deposit of color on the smooth surface, and the smooth surface was badly scratched.

EXAMPLE 2 A blue concentrated printing paste was prepared by mixing the following:

sults. No color streaks appeared on the cloth in areas intended to be free of color. After stopping the operation of the machine, it was found that the roller had no stickiness or pigment adhering to its smooth surface. The roller was not scratched. The doctor blade was found to be clean and free of pigment agglomerates.

EXAMPLE 3 The General Electric Silicone Resin 81182 used in Example 2 was replaced with an equal weight of Silicone Anti-foam Aa product of the Dow Corning Company. On running this printing paste in the intaglio rotary printing machine, satisfactory prints were obtained substantially as in Example 2.

EXAMPLE 4 A green concentrated printing paste was prepared by mixing the following:

Parts by weight Green Color Paste B 4000 Clear emulsion of alkyd resin R 4000 This corresponds to a typical one light concentrated printing paste. This was divided exactly in half, designated Part A and Part B. Part A was not altered in any manner. To Part B, consisting of 4000 parts by weight, one part of Dow Corning Anti-foam A was added. It was attempted to print Part A on a print machine and to print Part B on another print machine alongside the first under identical conditions.

It was not possible to produce satisfactory prints using Part A. Part 3 ran without any difiiculty. After therun, examination of the roller and-doctor blade revealed no deposits zof coloror scratching of the roller.: 7 A red fconcentrated printing paste wasinrepared by mixing the following: 1... r

Parts by weight Red pigment color pulp containing 80.0%

water and 20.0% red chemical pigment color 1000 Clear emulsion of alkyd resin 12 2200 This printing paste represents a printing paste containing 6.25 percent chemical pigment "color. By reference to the table, it will be seen that this is a three light, concentrated printing paste.

This concentrated printing paste was used to print cloth in our intaglio roller cloth printing machine. After 20 yards of cloth had passed through the machine, red streaks showed up on the cloth in areas intended to be white and corresponding to the smooth surface of the printing roller. The machine was stopped. The smooth portion of the intaglio roller was found to be sticky with the red color paste, although the doctor blade was properly adjusted.

To the concentrated printing paste on the machine 0.1% Dow Corning Anti-foam A was added, the doctor blade and rollers cleaned off and the machine again operated.

After the treatment with the Anti-foam A, a polysiloxane water repellant, the use of which is contemplated as an object of this present invention, the running of the machine continued, however, no red streaks of the red pigment appeared in areas intended to be uncolored throughout the entire run. On stopping the machine, the printing roller was found to be smooth and non-sticky. No further scratching had occurred.

The composition of the materials referred to by letter designation in the above example is:

Blue color paste A Parts by weight Phthalocyanine Blue 250 Alkyd resin solids) Water 600 Clear emulsion of alkyd resin R Parts by weight Glyptal Resin (50% solids in mineral spirits) 20 Mineral spirits solvent Water 800 Green color paste B Parts by Weight Phthalocyanine Green pigment 250 Alkyd resin (100% solids) 150 Water 600 What we claim is: 1. A process of textile printing from intaglio 7 engraved rollers, which consists in rotating the roller under a doctor blade to take up in its engraved areas a paste carrying 250 parts phthalocyanine blue pigment, 150 parts alkyd resin, 600 parts water and 3000 parts of an emulsion made by mixing 540 parts mineral spirits, 60 parts of alkyd resin, 2400 parts of water, and added thereto one part of phenyl-methyl siloxane polymer all parts by weight.

References Cited in the file of this patent UNITED STATES PATENTS Name Number Date Number Name Date 2,222,582 Jenett Nov. 19, 1940 2,416,620 Gans Feb. 25, 1947 2,467,858 Sage Apr. 19, 1949 2,504,136 Lee Apr. 18, 1950 2,523,065 Sage Sept. 19, 1950 2,571,029 Goodwin Get. 9, 1951 2,605,243 Sowa July 29, 1952 v OTHER REFERENCES Lacquer Emulsions, copyright 1935 by Hercules Powder 00., pages 1 and 3. 

1. A PROCESS OF TEXTILE PRINTING FROM INTAGLIO ENGRAVED ROLLERS WHICH CONSISTS IN ROTATING THE ROLLER UNDER A DOCTOR BLADE TO TAKE UP IN ITS ENGRAVED AREAS A PASTE CONTAINING BETWEEN 5 AND 13 PERCENT WATER INSOLUBLE PIGMENT, AN ALKYD RESIN MINERAL SPIRIT TYPE SOLUTION-WATER EMULSION WHEREIN THE ALKYLD SOLUTION FORMS THE EXTERNAL PHASE, AND CARRYING 0.0001 TO 5% PHENYL METHYL SILOXANE POLYMER ALL PARTS BY WEIGHT, AND DEPOSITING THE PASTE ON TEXTILE AS THE ROLLER ROTATES. 